Soultone 45ME3 impedance selector

[brk303]

I just purchased a Soultone 45ME3 and have a question about the Impedance selector. I emailed Mickey from Soultone, but maybe someone here knows too.

So, according to the user manual with EL34s and a 4 ohm cab, the impedance selector should be set to 8 ohm. Where as if I had KT66s and same 4 ohm cab, then the selector should be set to 4 ohm.

Anyone know if this is correct or if I misunderstood something ?